A new guest post by Geoff Russell — only mildly climate-change related, but definitely ‘food for thought’ in the context of sustainability of natural resources (and bad science)…

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The last couple of weeks have seen a few things tickle my particular itch … the linkages between nutrition, food security and climate change. The first is a long overdue piece in New Scientist on omega-3 oils by Sanjida O’Connell. I called these the new snake oil in Perfidy and the NS article does a good job of explaining the dodginess of the evidence for the many wonderous effects claimed for omega-3s.

Scientists come second in race to trawl southern oceans

In last week’s Southern Ocean story, Catalyst journalist Mark Horstman was embedded with scientists busily trawling (i.e., trashing) an area to find out what it contained so they could protect it. Don’t worry, I don’t quite understand the logic either. The theory seems to be that if you give people a list of what’s in an area they are less likely to trash it than if you just ask them politely to stay out.

But the NS article and the Catalyst piece became intimately connected by the first major discovery of the scientists … namely that they weren’t the first people to scrape a big metal frame with a net on it along the ocean floor. Some of the world’s fishing fleet had beaten them to the punch in an area supposedly protected by international law. The images of trawler scrape marks and dead ocean bottom were ominous. Why ominous? Consider the odds of the scientists just happening to drop their camera and trawl frame on the only trawled area in the massive expanse of ocean below the 60 degree latitude. It would be far easier to find a needle in a haystack. Clearly, plenty of trawling has been taking place, and we aren’t just talking about a few navigationally challenged lads in a tinny throwing a hook over. The trawl marks also show, of course, that preparing a species inventory is unlikely to keep fisher people out of the area because some already know what’s down there and they want it … so ends the case for the prosecution.

Climate change and hunting for fish

Capture fisheries, as distinct from aquaculture industries, are just wildlife hunting industries and wildlife is intrinsically unproductive … which is why hunter gatherers were displaced by farmers. The graph shows that capture fisheries are levelling off at about 100 million tonnes per annum. This is about 1/3 of the weight of terrestrial farmed meat, and has about 10 percent of that meat’s caloric value. Farming involves selective breeding, hormones, antibiotics, rubber gloves, artificial insemination and all manner of strategies to improve on mother nature’s relatively dismal productivity. Providing food for people just isn’t an evolutionary imperative.

The leveling off in capture fisheries shown in the graph hides the more detailed picture which is a gradual decline in the trophic level of fishery captures as a succession of crashes means a constant search for new species or new areas of the same species to replace those which have crashed. This just means that fish eaters are gradually eliminating the bigger fish at the top of the food chain and working their way down the food chain.

Ocean wildlife systems are extremely complex with food webs which have long subchains and many interconnections. Only in the North Sea are there decades worth of catch and survey data not only of the targets of human fishing, but of the fundamental supporters of the whole edifice, the little things, the microalgae and plankton communities. Correlations between the populations of a range of ocean animal communities are changing with temperature and interacting with human exploitation of the top predator … in this case cod. Analyisis predicts that the movement is toward a new system which is being dominated by jellyfish near the surface and crustaceans down deep. Some people will welcome the crustaceans, but jellyfish are a rarely aquired taste.

Other jellyfish increases are being measured in the northeast Atlantic and elsewhere. Jellyfish are predators of fish larvae, can kill fish in aquaculture net-pens and can do serious damage to power station water intake systems. They have a capacity to dramatically change ecosystem structure and function in ways people don’t enjoy … stinging doesn’t earn them many friends either.

Fish farming is growing at about 6% per annum and is filling the void left by this continuous stream of crashes in capture fisheries. Aquaculture is increasingly turning (human) food into (fish) feed. It has become yet another drain on the world’s grain crop, along with factory farms, feedlots and biofuels.

What drives demand for fish?

So what drives the global demand for fish and why, in particular, would fishermen face the formidable logistical and financial challenges of trawling a couple of kilometers deep in the southern ocean?

At a rough guess, it’s partly because every fresh faced wanna-be TV food guru tells people that fish is healthy because it’s rich in omega-3s. At a second rough guess its because the ACCC allows Meat and Livestock Australia to lie about omega-3s in red meat being brain food without sanction. At a third guess, I’d blame the not-so-fresh faced nutritionists at the CSIRO who are also happy to cherry-pick science to sell their fishy diet books. You may recall that CSIRO’s famous diet isn’t just a red meat diet, it also advises people to eat double the national average fish intake. This diet has been translated into 17 languages so it is effectively telling a substantial part of the planet that a diet which requires trashing oceans and emulating Australia’s world best practice deforestation and extinction rates to produce bucket loads of red meat is better than alternative diets which are more environmentally benign. The fact that this isn’t even an accurate representation of the scientific results doesn’t seem to bother them at all. A new Total Wellbeing Diet Book has just been launched confirming that CSIRO continues to advocate trashing the planet’s oceans and maximising every person’s greenhouse emissions above and beyond “mere” energy use despite some at CSIRO swimming against the tide by advocating against the Total Wellbeing Diet.

CSIRO’s plan to leverage fishery collapses

But the CSIRO has plenty of dogs in this fight for nutritional brand loyalty. This is a disgusting phrase, but it is appropriate given the CSIRO Nutrition Division’s ethical standards. CSIRO are working to engineer plants to produce long chain omega-3s in bulk to take up the slack when their obedient customer base has finished exploiting not just our ocean but anybody else’s who will trade with us. A nutritionally honest message that nobody needs fish would undermine the market for these new products.

It doesn’t matter to CSIRO that the only big meta-analysis of the impact of omega-3 oils on heart attacks showed no benefits. This was done by a group called the Cochrane Collaboration. These people are rather different from many researchers, most of whom have done just a smattering of statistics during their undergraduate training. The Cochrane people are specialist statisticians and, just like in those John West salmon ads, it’s the studies they reject that make them the best. The Cochrane people may not be infallible, but CSIRO’s nutritionists need more than just good sales figures to take them on. They need evidence.

Similarly, it doesn’t seem matter to CSIRO that there have been large IQ gains over many decades in many countries which are demonstrably not due to fish. And it doesn’t matter to CSIRO that people who don’t eat any fish have lower heart attack rates than people who eat fish … I’m talking about vegans and most vegetarians. Don’t tell anybody, but some vegetarian Indian populations are letting the side down by clogging their arteries with ghee. Saturated fat by any other name still works its magic.

The Great Barrier Reef coral spawning pales into insignificance beside the seas of omega-3 hype spawned by TV foodies, CSIRO, Catalyst and even MLA, and this hype drives up the demand for fish.

Australia already imports over half the fish eaten here. We buy them from somebody else’s ocean. The same is true in many other countries where the omega-3 myth is rampant. The current mechanism whereby collapses in one fishery are replaced by a new one is unlikely to continue for long. Fishers have to run out of new fisheries some time, and fishing the Southern Ocean does rather smack of desperation.

Other omega-3 myths

But the New Scientist article provides a summary of the myths that cling to the omega-3 brand like barnacles to a pylon. In brief:

Omega-3 might delay alzheimer’s in rats, but large human studies have once more demonstrated that people aren’t rats. Back when I served on the Flinders University Animal Experimentation Committee, they were (and probably still are) doing plenty of work which involved giving strokes to rats. There are dozens of really good drug treatments which work wonders on stroke in rats. None of them work wonders on people. People are not rats.

When ever the micky mouse studies showing that extra omega-3 intakes improve spelling, reading or something else are done properly, they fail to find any effect.

… etc

The Maasai and omega-3s

There is one more wrinkle in the omega-3 story which also emerged last week. The Maasai. That’s right the tall bouncy African tribal group who live on blood and yoghurt … except they don’t eat much blood, if any, and haven’t done so for decades. A press release from Jena University announced that the Maasai had a perfectly healthy amount of omega-3 fatty acids in their red blood cell membranes “even though they are not ingested“. Many Maasai live on milk and maize-meal porridge … neither of which contains any long chain omega-3s (see appendix below).

The full paper by Nadja Knoll hasn’t been published yet but it promises to be an interesting read. But I’ll bet it won’t stop the trashing of the oceans in pursuit of fish to sell to CSIRO diet aficionados.

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Appendix on Omega-3s: Omega-3s are polyunsaturated fatty acids which come in various lengths. The short ones are in all kinds of foods and we use them to make the long ones. Some animal foods, for example eggs, contain a small amount of short omega-3s and a large amount of long omega-3s. Plant foods can contain 50-100 times more short omega-3s but no long ones. Similarly, milk contains no long omega-3s. The advocates of increased omega-3 intakes are talking about the long ones … the ones in the products they sell or in the products their funding sources sell.

The Maasai, mentioned above, traditionally feed their children nothing but cows milk (following weaning) until about 5 years of age. The long chain omega-3 intake advocates believe that the process by which we make long omega-3s from short ones is inefficient and that it is therefore desirable to eat the long ones directly in meat and eggs. There is also a nice story about omega-6 oils competing for the enzymes required to turn the short omega-3s into the long ones. Google the net and you will find another famously inefficient molecule, this time an enzyme, called RuBisCO. It manages to drive all plant growth on the planet despite being inefficient. Nature is full of inefficient processes that seem to get the job done.

Awesome stuff! This interests me on two levels. Firstly, I am a failed fish farmer. Back in the late 70s I was growing rainbow trout in Greenwich (the zero meridian) using Thames water. The farm produced excellent quality trout in commercial quantities although not cost competitive. I was very well aware that trout as predator fish need a high protein diet so I was looking for sources of high protein food that were not attractive for direct human consumption.

Although this farm was closed in 1981 it contributed to identifying sources of pollution in the Thames, thereby changing the river for the better. In the late 1950s there were no vertebrates in the upper tidal reaches. Twenty years later it was possible to grow trout and today there are more than 100 fish species including the occasional salmon. This shows that even appalling levels of pollution can be reversed.

I later set up a fish farm in Eastport, Maine rearing Atlantic salmon smolts. This operation went belly up, taking my savings with it thus forcing me to get a job in a research laboratory in the USA.

My second interest is in the dietary value of fish and here I must respectfully disagree with your conclusions. Ten years ago I began to suffer from painful arthritis in every joint. Drugs proved successful but I had misgivings about taking powerful NSAIDs on a daily basis for the rest of my life so I experimented with different diets.

When on a diet low in animal fat (no dairy products, hamburgers, pizza etc) and high in oily fish (herring etc) I found that the drugs were no longer needed. While I have no idea whether this outcome relies on the Omega 3/Omega 6 ratio or something else, whenever I have a couple of hamburgers the pain comes back the very next day.

“Fish is good for us. Fish has omega-3. Therefore omega-3 is good for us”. A famous fallacy. I seem to remember the same with carrots and beta-carotene. There’s a good reason that we might find seafood beneficial: humanity is much more at home in the water than other apes [though we can maybe guess that people living near the coast kept getting smashed by tsunamis and we are mostly descended from people who moved up the rivers]. Wild fish are very random (e.g. mercury levels) so positive effects are likely masked by negative. Also our ancestors probably mostly ate shellfish.

The trawl marks could have been made by an earlier unknown scientific expedition. Long distance fishing is yet another example where people assume that in the future there will be cheap liquid fuels. That applies not only to fishing trawlers but the combine harvesters that help produce our daily bread. I’ve suggested before that in a few years that those who operate big machines could suddenly discover natural gas as an alternative to diesel. Australia alone may need tens of millions of tonnes of gas a year for that purpose . That will worsen the economics of gas fired electrical generation.

The other issue with polar fishing is that of food security. When a country needs to import bananas that is less threatening than basic protein sources. We now have Japanese trawlers visiting the Antarctic the same time live cattle are shipped to Indonesia. I suggest all countries should be capable of feeding themselves to a basic level. When there is no diesel fishing half way across the world is no longer an option.

Gallopingcamel: People normally don’t need fish or other long chain
omega-3s. But there are medical conditions which require it. E.g., some people
have an enzyme deficiency which makes LC omega-3 intake beneficial. In
arthritis, the ratio of omega-3/omega-6s in your diet (I’m not talking long
chain here but short chain) can affect the symptoms … pain/inflammation. You
could achieve the same result without the oily fish.

John: The idea that there are “basic protein sources” is fundamentally
misleading. People need food. It’s very difficult to get protein deficiency
when your caloric intake is adequate … but if your caloric intake is
inadequate, then all the protein in the world may not save you from problems.
e.g., Maasai children surveyed in 1982 had a significant stunting
rate (~20%). They were getting ~200% of the recommended protein
intake for their age but not enough calories …

Now, one of the sillier aspects of the Vertical Farm concept has been trying to run the thing on renewable energy and biomass. But imagine this concept running on a reliable nuke!? These towers would be largely pest free, climate controlled, super-water efficient, and almost create their own internal ecosystems. There could be synergies between sewerage reprocessing, local city council biomass / lawn clipping green bin collection and processing, and local food security. The sewerage and local biomass waste goes in, and the food comes out.

Right in the hearts of our cities.

The Vertical Farm has been attacked by various agriculturalists I know on the Sustainable Population Australia forum, but it mainly appeared to be based on the energetic value of the local city council’s biomass collection. It was the old ERoEI of the tower they were worried about. Backed by a clean, green, nuclear grid that would no longer be a concern, and it would all come down to the economics.

“Despommier suggests that, if dwarf versions of certain crops are used (e.g. dwarf wheat developed by NASA, which is smaller in size but richer in nutrients[16]), year-round crops, and “stacker” plant holders are accounted for, a 30-story building with a base of a building block (5 acres) would yield a yearly crop analogous to that of 2,400 acres of traditional farming.[11]”

Vertical farming is idiotic. Farmland is very cheap and there’s no shortage of it. City land is crushingly expensive. Large engineered structures are expensive.

If you’re doing artificial illumination you have to deal with the fact that plants are about 1% efficient at converting light into biomass and that only a small fraction of that biomass will be food.

If you’re using sunlight for illumination you need some kind of expensive lightguide system to diffuse it evenly across all plants on all floors.

The only crop economically suitable for vertical farming is Marijuana and maybe genetically engineered crops that produce designer drugs.

I can invent in five minutes a whole slew of CRAZY ideas which are still a lot more realistic than vertical farming.

You could develop mushrooms or bacteria that much more efficiently and cheaply convert cellulosic biomass to food(mushrooms already do this, but not very efficiently and not all kinds of cellulosic material).

You could farm algae, supply them very cheaply to tens of thousands of food scientists and enterprizing amatures and see what they can make of it. The starchy seeds of particular kinds of grasses are not very delicious but we managed to turn them into a main ingredient in an endless variety of delicious breads, cookies, pastries, pasta, white sauces, batter, beer, booze, gluten based fake meat and animal feed. Who knows what we can do with green slime?

You could mass produce water-efficient greenhouses and expand the arable land into much dryer areas of the world.

You could invent some geoengineering scheme to green the deserts.

You could figure out some way to make artificial mitochondria that recycle ADP + phosphate back into ATP(the energy currency of the cell) in the same way that mitochondria do through metabolism. The difference being that these artificial mitochondria would not use oxidative metabolism, they would use resonant inductive coupling to wirelessly recieve the energy required from an external source. This would reduce the need for aerobic metabolism, a leading cause of cancer and a suspected primary cause of aging; reduce the need for food calories.

You could invent some kind of entertainment system that simulates the hedonic thrill of eating as much delicious food of any kind you want. This way the people who adopt this tool will be freed up to make food choices based on health, cost and environmental consequences rather than hedonic pleasure and will no longer binge on meat and junk foods.

I take your point about plants only being marginally effective with the sunlight they get, but here’s the thing: on the *right* plot of land, with the right windows during daylight hours and grow lights at night (for 24 hour growing), you have a 24 hour completely controlled growing system that is independent of the vagaries of climate changing weather. Some might argue that Vertical Farms are to traditional farming as nuclear power is to renewable energy!

However, greening the desert is not that crazy a scheme. The Seawater greenhouse can not only desalinates enough seawater to grow food in the cooler shade of the greenhouse, but can release 5 times the water it uses for its own food.http://www.seawatergreenhouse.com/

This water could then also be used to green outside those greenhouses using the following approach.

During my fish farming days I tried raising eels but it was slow going owing to low water temperature. Some ingenious folks at Hinkley Point solved the problem by using warm water from a nuclear power plant.

RobertSmart: Your famous fallacy is worse than you think. The premise is … searching for the right word … sloppy. Marion Nestle has a couple of
good chapters on the politics and science
of claims that fish is healthy in her “What
to eat”. The US FDA resisted for some decades allowing people to make
claims about fish being healthy, because the evidence wasn’t strong and
consistent. The Cochrane meta-analysis I mentioned in the article
isn’t just of omega-3 oils but also considers well conducted studies using fish.
The problem historically with plenty of early fish epidemiology is that
rich people eat more fish and rich people have better health and live longer
than poor people anyway. The fish reputation was built before more
modern and better controlled studies were done.

Barry: The connection with climate change is somewhat tangential, but suppose people take Hansen’s call seriously to undo 200 years of deforestation. Then this means less red meat (at the very least).
I’ve met a few people whose
response is “That’s okay I’ll just eat more fish”! Such a response would
add considerably to the current pressure on fisheries if widespread.

Verticlefarms: I’ve read news reports about these but haven’t looked into
them. Certainly the integrated fish/chicken/pig farms of China are a
disease generator of great potency and any attempts to integrate animals
into the verticlefarms will suffer from such problems … in addition to the
additional ethical issues associated with confinement systems.

As cheap oil, phosphate and irrigation water all decline while populations increase I wonder how urban farming will farehttp://en.wikipedia.org/wiki/Urban_agriculture
Perhaps root crops like spuds will supply more of our calories replacing cereals grown way out of town. With urban farms it may be more practical to use sewage sludge as a soil improver despite contaminants. More humane fish and poultry operations could integrate with urban farms if strict disease protocols are in place.

The trouble is few cities are willing to rezone swathes of land until they are in trouble, Detroit USA being an example. Most cities with degraded areas keep hoping for development to come back. The issues parallel the questions on other threads
– what happens to wind and solar when there is no gas?
– what happens to farming and wild fishing when there is no diesel?

What percentage of the diesel do we use for agriculture, and why will we not be able to meet that from a combination of:-
* syngas (from biochar)
* algae (from sewerage and pumped / processed etc with nuclear)
* 2nd generation biofuels
* ELECTRIC harvesters? What’s the potential for more efficient use of fuels through fuel cells? What about hydrogen fuel cells (with the hydrogen manufactured with the plentiful power of nuclear energy) if all else fails?

The current liquid fuels emergency act of the IEA demands that nations prioritise fuels to the most important sectors. If you want to worry about an industry that will probably go down first after peak oil, I’d be more concerned about the airlines. I think food production will be the [i]last[/i] to run out of diesel.

An interesting post. It is generally accepted that, in man and many other mammalian species, there are really only two essential fatty acids (EFAs) (linoleic and alpha linolenic). These are both short chain polyunsaturated fatty acids (PUFAs). The former is part of the omega 6 series and the latter, omega 3. In the body, these are chain elongated to produce biochemically essential long chain PUFAs. One can by-pass chain elongation by consuming the long chain PUFAs directly and they are sometimes considered “conditionally” essential. In passing, I should mention that cats, specialist predators, can’t chain elongate sufficiently (or at all) to produce arachidonic acid (omega 6 series) and show deficiency signs without meat diets. It could be that there are some humans for whom this is also partly the case.

I think that most of what you wrote was accurate but was, to an extent, being used to bang your vegetarian/vegan/animal liberationist drum. I think that you failed to highlight the important matter of omega 3: omega 6 ratios with respect to human health. Most modern diets contain far more 6 than 3. Oils from green leafy materials are rich in 3 (alpha linolenic) but most seed oils (linseed an exception) are deficient with linoleic predominating. This has raised concerns relating to human health. Nevertheless, I think humans (certainly poultry) can certainly not only chain elongate but switch from 6 to 3 (or vice versa). Thus, a source of linoleic acid (omega 6 series) in sufficient amount can usually provide for the synthesis of adequate essential long chain PUFAs in both the omega 6 and 3 series. The important point to address is whether this is always the case.

I am sure you are thus accurate in what you say about the Masai and diet. However, those of us with inadequate levels of long chain omega 3 PUFAs in our systems would benefit from dietary fish oil (or, possibly, dietary alpha linoleniic). Do you know how many in the population fall into this category? I would be much more comforted by this sort of information than by reliance upon a statistical survey before dismissing the benefits of fish oil. That said, I would not wish to argue that the virtues of eating fish have not been over-promoted by advertisers.

I also worry that you suggest that, given an adequate diet in respect of energy, protein deficiency is very unlikely. This may be true for adults at maintenance and for those who are active. It is not necessarily the case for those that are growing, breeding or lactating. It is especially not true for vegetarians. It is obviously perfectly possible for vegetarians in all physiological states to construct diets which are adequate in all essential amino acids (EAAs) but there is considerable scope for cock ups.

Hi Douglas: Not at all pedantic. I’ve submitted a paper to a journal which
covers some of the issues you raised and a less formal version might get
on BNC some time. There are plenty of claims about ideal ratios of
omega-3s to omega-6s in the diet, but they are not based on epidemiology
but biochemical considerations. ie., it is said that 1:1 is ideal, but that the
current western diet is about 1:10. Vast numbers of people live healthy
lives into their 70s and beyond without having this “ideal” o3:o6 ratio,
so what the hell does it mean? Would they live 5 years longer with the
right ratio? 10 years? Nobody has data on this stuff … or if they do, it
is well hidden. Many of the studies are rat studies or very small. Are
there any genetic subgroups who can’t build long chain fatty acids from
short chains? I’ve seen an oblique comment about this in an article
but I’m still chasing data … so far nothing.

The claim about “no protein problems when energy intake is adequate”
will fail in some circumstances (certainly a coke and crisps diet should
do it), but the idea of a global
or 3rd world protein shortage was exposed as rubbish back in the 70s.
There are groups with too little food and poor drinking water … that was
and remains the problem. The Lancet published “The Great Protein
Fiasco” in 1974 with a followup in 2000. They aren’t
freely available on-line or I’d link them. All over the world there are
people living on staple diets based around low protein foods … like taro,
rice, sorghum. Many of these diets are poor and cause problems, but
not, when they have enough food, protein problems. It will be interesting
to see the new Maasai work, I linked to the 1980s study above. Have
a look at that work Douglas. It’s a great example of Boverty.

Geoff, I looked at the press release of the Masai study to which you linked. I am surprised that the release appeared to put such emphasis on the fatty acid status of the subjects. I am also surprised that the German professor should have been surprised to have “discovered” that her experimental subjects were not evincing any evidence of omega 3 deficiency. She shouldn’t have expected it, given that the Masai typically consume more milk than most other tribes and that the milk they consume comes from grass fed cows. The situation might have been different if their cows had been fed concentrates, even though cows fed the latter would yield far more milk. Had I been conducting a survey on the adequacy of Masai diets, omega 3 status wouldn’t have rated highly but, I am sure the good professor looked at other factors as well – they were just absent from the release.

I tend to agree over the boverty issue in Africa, provided there is access to infrastructure/water that allows relatively intensive farming. However, It’s easy to understand why many tribes from arid areas came to rely on cattle and small ruminants to meet their nutritional needs, lacking as they do, the means of digesting high fibre diets directly.

Geoff Russell and Doug Wise,
How can I find out whether it is the Omega 3 content of fish that is controlling my arthritis pain or some other constituent? Are there any commonly available cooking oils that would have a similar effect?

I have never heard of anyone deliberately consuming linseed oil but maybe that is just my ignorance.

gallopingcamel: Yes, linseed (flax seed) oil is edible and is marketed accordingly. It doesn’t taste that good. It is a rich source of alpha linolenic but it is almost certainly (barring placebo effect) the longer chain omega 3s that are helping you. As less than a fifth of linolenic will end up as long chains, you may need to consume five to ten times more than of fish oil. As a halfway house, you could look into the vegetarian omega 3 pharmaceutical made by Croda. It’s all on Google if you want confirmation.

gallopingcamel: veg*ns who have been sold on omega-3s take flax seed oil,
usually in capsules because it tastes fishy otherwise (!)… as does
bread containing the same. A couple of well credentialled
nutritionists have just put out
a book called “Becoming Raw”. Its about raw vegan diets. I don’t
support such diets because they don’t scale well, but the book is excellent
with plenty of information on this and many other issues. You will
find all sorts of ways of
changing your o3/o6 ratio that you would never have dreamed of
(and probably won’t try :) … whether it is this or the long o3s which is
controlling your pain is very complex and if anybody really knew the
answer, there would be no shortage of effective arthritis drugs.

I thought the evidence was that human beings had biologically adapted to their countless millennia of cooking? Not an issue I’ve read lots about, but just the latest reports to Scientific American podcast…

Sure, benthic trawling does trash the seafloor. The benthic trawl use off the Aurora Australis as shown in the Catalyst program was 2 metres across, small in comparison with beam trawls used by commercial operators. Commercial beam trawls come in several sizes up to about 12 metres across and two of these can be towed in tandem. Considering the area of the Antarctic continental shelf and the upper continental slope is nearly the same as the area of Australia, the impact of the infrequent scientific trawls is tiny. The discovery of new species and communities by such trawls has been substantial. Vast areas of the Antarctic continental shelf are scoured by icebergs every year. The recolonization of these scours is a study in itself.

As for the odds of finding evidence of earlier trawling being “far easier to find a needle in a haystack”, nothing could be further from the truth. Bruce Rise, where the scrape marks were seen, has been known since 1914 as a shallower plateau on the continental shelf and therefore a likely hotspot for fish. This is one of the reasons it being closed for fishing. To imply that all of the seabed south of 60 degrees South has been worked over and scrape marks are to be expected is erroneous. Understanding benthic communities is essential for management of fisheries. A major problem in Antarctica is the illegal, unreported and unregulated (pirate) fishing. But that’s another issue sadly overlooked in this piece.

Geoff
Sanjida appears to be in “Denial” over the health benefits of Omega-3’s. The benefits on the Cardiovascular System are well known (heart rate, cholesterol levels, plaque formation) – maybe those ghee eating vegetarians in India should take note. Gallopingcamels relief from arthritic pain is no doubt as a result of an increase in the anitinflammatory series 3 prostaglandins achieved from his Eicosapentaenoic acid intake. The article for all intents appears to be a hatchet job. Someone mentioned here that Scientific America had descended to the quality of National Enquirer – I agree.

The main problem is that you are not going to get society to eat to the standard that you believe they should, any attempt at reducing/avoiding disease states via natural products therefore should be applauded.

Harvey: Point taken. A scientific trawl is smaller and yes I did wonder
how the trawl site was chosen and clearly it wasn’t a random sample!
I didn’t mean to imply that all of the seabed had been worked
over, but I’d bet a bottle of your favourite poison that this “known hotspot”
isn’t the only known hotspot to have been trawled. How many likely
hotspots are there? If you know then you can do the sums.

I thought about saying something about illegal
fishing, but figured I get into serious trouble if I said what I think about
the subject and the piece was longer than I wanted anyway … takes
a deep breath … back in the
late 1980s there was a study in Canada “Monitoring hunter performance in prairie Canada.” Trans. N. Am. Nat. Wildl. Resour. Conf. 52:233– 245. (can’t find it online). They watched duck hunters from hidden hides (as opposed
to unhidden hides), scored their wounding rates, shots at protected species, etc and then surveyed the hunters (who didn’t know they had been
watched) … asking them about their activities. Put simply, many
hunters lie … frequently. Is this surprising? It’s like those declarations on
envelopes “Are you posting a bomb?”. Why would people who enjoy killing worry about a minor indiscretion like telling lies? I’ve had more
experience with hunters than fishers, but people who’ve dealt with both
tell me that fishers are worse. I could probably dress up my personal
experiences and the Canadian stuff with data on Russian whaling fleets
and lying at a high level, or Japanese tuna fleets. Also throw in stuff
about meat substitution rackets (has anyone ever heard of a vegetable
substitution racket … silverbeet being sold as spinach perhaps).

Try this test. Take a dozen premium quality lobsters to the pub any night you
like. Put a ridiculously low price on them and see how many people
buy them and how many people report you to
the authorities as a likely illegal fisher.
When you can’t sell those lobsters, you will have a chance at
stopping illegal fishing … not before.

TeeKay: most of the world’s calories are provided by foods that are best cooked … mainly grains. Cooking also kills all manner of pathogens and is particularly
useful where the water supply is dodgy … a sadly large part of the planet.

Gordon: I noticed you didn’t have any evidence for your criticisms of the
New Scientist paper. Lot of things which are “well known” are wrong.

Geoff:
The SA paper cites a “review” preformed in 2006 by Lee Cooper that concluded that Omega-3’s do not offer a significant protective effect against cardiovascular disease. This is contradicted by two other reviews, also conducted in 2006, which both indicated decreases in total mortality and cardiovascular incidents.http://www.ncbi.nlm.nih.gov/pubmed/16825676 & http://www.ncbi.nlm.nih.gov/pubmed/17047219. Is Dr O’Connell being balanced ? I think not. At least she acknowledges that “DHA is vital for human health” – just don’t get it from fish!

Thanks Gordon. I’ll have a look at those studies.
There are various questions
at issue here:
(*) Is fish, (particularly in a warming world with reductions in some
fishery output) a scalable food? ie., can everybody eat 500 grams of
fish per week as advised by CSIRO? Definitely not.
Current global output of demersal and pelagic fish is about 120
grams per week per capita and I’m not sure
how many of these would be classed as high (enough) in o3.
(*) Is fish required for good health? There is no shortage of data
here and the answer is no.
(*) Can meat eaters avoid some of the consequences
by adding (more) fish? This isn’t a slam dunk for either heart disease
or bowel cancer.
(*) Will attempts to grow aquaculture to meet a higher
demand by rich people for fish impact the food security of the poor?
Definitely and adversely.
(*) Will long chain o3s be useful for people with various
illnesses? Quite likely.
(*) Does the high demand for fish drive illegal fishing? Obviously yes.
(*) Do fishery managers know how to safely manage fisheries for
sustainability? The track record isn’t good.

gallopingcamel – I have nothing against Scotch, or Irish whiskey, but a good Canadian rye, like Alberta Springs, or Wiser’s, can stand up to the best of them. If the only Canadian whisky you have had are Canadian Club and Crown Royal, I don’t blame you for thinking ill of them; we don’t send the good stuff overseas.

Gordon: The Mozaffarian paper had interesting data on how much of various
fish/seafood you need to eat to get what the authors thought was a reasonable
amount of long chain o3s (for people who haven’t read
the paper the amount they recommend is 250mg/d EPA+DHA). The amount of
fish/seafood required to get this ranges from 1.1 kilograms (cod and catfish)
down to 140 grams (tuna/salmon) … both figures are PER WEEK. With
prawns/scallops at about 500 grams. This is a huge range. I haven’t
done a more careful calculation, but my guesstimate above still looks reasonable
that wild fisheries can never supply this and farmed fisheries could only do
so by compromising human food supplies.

As far as the health impacts are concerns. The Mozaffarian and the Hooper (Cochrane collaboration paper lead author referred to in post) agree fairly well
on mortality impacts … about a 15% reduction in risk of death for people
eating the most compared to people eating the least. Its always nice to
find agreement. But Mozaffarian didn’t
look in detail at actual events … heart attacks. The bottom line is that
eating more fish won’t prevent the heart attack but may reduce your
risk of dying a little. This is hardly impressive considering the
catastrophic cost to the
world’s aquatic animals … the cost being far wider than just the
fish killed, but also the bycatch of non-target animals including
birds, marine mammals and the like.

I have to admit to being annoyed when people pretend to care about
health but ignore the fact that if this is a major interest then most
people can reduce
their risk of heart attack to very close to zero and even reverse
atherosclerosis without eating fish.

The per capita calculations you make simply do not apply as you will never get everyone eating fish (particularly in India). Also keep in mind that the bulk of the Omega-3 market is supplied from sustainable species, Peruvian Anchovy, caught with selective fishing gears in accordance with FAO (Food and Agriculture Organization of the United Nations) standards which avoid the incidental catch of threatened species and prevent negative effects on the sea floor.

I have to admit to being annoyed when people simply dismiss products like omega-3’s as Snake Oil and fail to acknowledge that “at risk” groups can benefit from it’s inclusion in their diet, something that is backed by science.

Gordon: There’s always a problem when an meta-analysis of 48 randomised
and 41 cohort studies is contradicted by a study like Siscovick et al which
wasn’t included in the meta-analysis. I’ll go with the former. I’m happy to
hear about the source of o3 and presume you are talking about supplements.
But the million copies of the Total Wellbeing diet aren’t telling people to
take o3 supplements, but to eat fish/seafood. Sure, my little calculation
was more rhetoric than science, but you don’t need any calculations to
realise that the oceans aren’t supporting current demands for fish, let
alone those of the CSIRO’s diet book selling to 17 language
groups. We clearly get annoyed by different things. Here’s another
thing that annoys me. Australians have a brilliant food supply. We
produce more than enough food for everybody to be healthy without
fish. To our north is a country with rather a lot of people and a
grossly inadequate food supply. To Indonesia, fish isn’t an optional
extra but a vital part of a food supply. I’d prefer their food supply
to be different, but currently that’s the situation. But if they fish in “our” waters
we burn their boats. How evil is that? They, for their part, rip the fins
off sharks and throw them back to die. How evil is that? We could sell
Indonesia more cereals, but who’d sell cereal overseas to poor
people when you can sell to a pig farmer or wagyu beef feedlot
operator?

A friend of mine recently had a heart attack. Thanks to good
ambulance officers he survived. He thought he was safe because
he ate fish regularly and was fit and not fat. He couldn’t quite believe the angiogram results. This is the crock that the general public has been sold.

” “at risk” groups can benefit from it’s inclusion in their diet, something that is backed by science. ”

While probably true, it obviously doesn’t mean immunity to their ailments, and it’s far from the best option. It would be far better if people ate better food to begin with and actually exercised. Lack of omega 3 is hardly a leading factor in causing heart disease.

A 4 times increase in fishing globally to meet CSIRO’s 500 gram per week recommendation would be a heinous conservation crime.

Geoff:
Firstly, sorry to hear about your friend, that is something nobody wants to experience. I guess the big crock here is the fallacy that mainly fat people are the ones prone to heart attack – the statistics show a different picture with just as many thin people being hit (genetics?).

I was talking about supplements and to be totally honest I have not read the CSIRO Total Wellbeing diet (nor do I intend to) but I would imagine that like all good diets it will soon be forgotten! I agree with you that Australians have a brilliant food supply but it is being undermined by international interests pressuring us to source from the global markets. It won’t be long before we become “dependant” on imports.

I’ve spent a bit of time in Indonesia and Ikan (fish) isn’t the main protein. Ayam (chicken) and Sapi (beef) rate highly and depending on your religious persuasion, Babi (Babe :-) (pork) is also popular. A lot of people up there I know, but the quantities of food consumed are a lot less than what we would “graze” on. I like how you preference “OUR” waters, as our maritime border has been something of contention with our neighbors (particularly the Timorese), I think even the Portuguese have had a go at us about our “Maritine Boundary”.

Corby’s, is a Canadian distiller of small batch whiskies that was noted for their excellence and craftsmanship, however they were bought out by Hiram Walker a few years ago. Royal Reserve was one of their, shall we say, more commercial blends, that at least in the past was made with some of their finer single malt offerings.

I have tended to avoid these types in general because most of them now have corn (maize) foundations, with little actual rye present to impart some flavor. This is what happened to Crown Royal which once was the standard-bearer for Canadian whiskey.

This is why I look for those products that are still 100% made of rye, and aged in real oak. Corby still makes three of these, Lot No. 40, Pike Creek and Gooderham & Worts. What the status of Royal Reserve is at this time, now that they have been bought by Walker, I cannot say.

Gordon: The main protein food in Indonesia is rice … 22g/cap/day, the combined contribution of all meats combines is 3.4g/cap/day with fish/seafood coming in at 6.9g/cap/day (FAOstat). The food supply is 53 g/day/cap of protein. And that
figure includes waste, so is above the amount actually eaten. Total calories per cap/day is just over 2434. As a food supply figure this isn’t enough, which is
why Indonesia has so many malnourished children (and adults). The 42 calories per day per cap from fish are not optional extras in the food supply like they
are in the places eating most of the worlds fish. The same is true in many coastal
communities in Africa … but the big factory fishing fleets are buying+stealing
the fish, exacerbating the problems. AND, of course, Indonesia doesn’t have an equitable food system (nor does anywhere else), so the fish+meat won’t
be evenly distributed. Beef is pretty well an irrelevancy at 0.7 g/day/cap of
protein, except
that Indonesia’s 11 million cattle cause a lot of deforestation. Probably
far more than palm oil … but I don’t have any data … but they have to live
somewhere! Like I said, our response to malnutrition in Indonesia is
to burn their fishing boats. Go OZ.